Environmental Sizing Needs Urgent Policy Encouragement

In 1997, for textile sizing, "little use, no PVA" is the starting point.

After more than ten years of appeal and active promotion, with the increasing emphasis on environmental pollution from all walks of life, the industry has made great efforts.

But as Gao Weidong, vice president of Jiangnan University and director of textile and sizing Specialized Committee, pointed out that due to the existence of various constraints, there is still a long way to go to achieve PVA sizing.

It is still a long way to go to further upgrade to "environmental sizing" on the basis of "no PVA sizing".

Promoting environmental protection sizing has entered a crucial stage.

Cost factors dominate enterprise selection

The target of "no PVA sizing" has been put forward for more than ten years. Although the proportion of the application of PVA slurry is gradually decreasing, it is estimated that at present, the annual dosage of PVA in textile sizing is still up to 150 thousand ~20 million tons.

At the 2011 meeting of the national slurry and sizing technology, there were still some business representatives who questioned the need not to use PVA at all.

What are the main reasons for pushing up the environmental resistance?

Wang Hongtao, deputy general manager of Luoyang white horse Refco Group Ltd, believes that the main reason is that the attention of the upstream and downstream enterprises to environmental protection is not enough. It is not known that environmental sizing will determine the survival of enterprises and affect the sustainable development of the industry.

Zhu Beina, President of the China Cotton Textile Industry Association, believes that at present, the textile enterprises only pursues the reduction of slurry cost and the pursuit of loom efficiency. The printing and dyeing enterprises only focus on the cost of raw materials for the purchase of grey cloth, and do not attach importance to the cost of sewage treatment, resulting in non degradable slurry still occupying the market.

In the absence of PVA environmental monitoring, the slurry cost is still the key factor that decides whether enterprises choose or abandon the use of PVA.

Reporters learned that this year, PVA prices fluctuate drastically.

When the price of PVA rises, the cost of sizing is reduced after enterprises use PVA slurry. Some enterprises have improved their enthusiasm. Once the price of PVA falls, the profits of low cost drive some enterprises to return to PVA.

In this regard, Wang Hongtao believes that enterprises must realize that environmental protection sizing is not a cost problem, but decides the future survival of enterprises, and we must prepare for it and act as soon as possible.

Xiao Wei, general manager of Jiangsu Yulun Textile Group Jingjiang Yufu Textile Co., Ltd., said that at present, cotton textile enterprises have no PVA sizing, and they rely entirely on the sense of social responsibility of their leaders. However, the risk of producing high quality varieties without PVA sizing is still borne by the cotton textile enterprises.

Especially in the current textile situation is very difficult, cotton textile enterprises have not received the printing and dyeing enterprises to reduce the cost of desizing and reduce the benefits of carbon emissions.

In addition, when weaving enterprises use environmentally-friendly slurry, some of the printing and dyeing enterprises do not understand. In the process of desizing, there is no corresponding process.

Due to the lack of emphasis on environmental sizing, coupled with the current lack of incentive policies and corresponding restrictive measures without PVA sizing, there is a lack of market driving force for environmentally friendly sizing.

Many experts suggest that the government introduce relevant policies, reward environmental protection enterprises, and limit the use of non environmental slurry such as PVA through environmental protection tax.

Who can replace PVA perfectly?

PVA has been verified in sizing process for many years and is a good sizing material.

According to experts, PVA has excellent film-forming property, adhesiveness and compatibility with other sizes. It has been a good sizing agent for high count and high density pure cotton yarn for many years.

Especially in the sizing of T/C, its performance is far beyond other sizes.

Now, in the pure cotton 40 and below, polyester cotton general products have also been basically achieved without PVA sizing, product quality is stable.

But pure cotton high count, high density and high density polyester cotton special products can not be completely used without PVA sizing.

Sizing is the foundation to ensure sizing effect. In order to further promote the process without PVA sizing, enterprises are concentrating their efforts on the development and application of new sizing agents.

At present, there are many kinds of pulp for so-called PVA replacement in the market, and their application results are all good and bad. However, the environmental protection slurry with high technical content, excellent performance, high reliability and industrialization instead of PVA is hard to find, and can not meet the needs of textile enterprises.

At the annual annual conference of sizing and sizing technology, textile enterprises hope to have more environmental sizing agents available for screening.

In addition to PVA, modified starch and polypropylene size are the most widely used pulp in textile enterprises.

Modified starch has good biodegradability, can form a certain strength of serous membrane, and has a certain penetration and adhesion to the yarn, and the dosage is the most, but the starch film is hard and brittle.

After application and practice, although the sizing performance of modified starch slurry is increasing, there still exist problems such as aging gel and so on.

Acrylic size has the characteristics of strong film toughness, stickiness, good permeability and easy desizing, but because of its high moisture absorption and high price, it is generally used as auxiliary sizing agent for sizing.

Shi Bosheng, chief engineer of Tianhua enterprise development (Suzhou) Limited, said that although significant progress has been made in the development of new slurry replacement for PVA in recent years, there have also been some tendentious problems.

The most prominent problem is to replace PVA with non environmental slurry, which is contrary to the fundamental purpose of promoting sizing without PVA.

He reminded us that the degradation of terephthalic acid after polyester pulp degradation is not only poor, but also toxic.

PVA itself is non-toxic, so polyester pulp is more environmentally friendly than PVA.

At present, the production of polyester sizing is increasing, and the implementation of environmental protection sizing has formed a new resistance.

Environmental protection can not be separated from process support.

The purpose of sizing is to meet the weaving quality of yarn in weaving process.

The sizing effect depends not only on the size of the pulp, but also on the quality of the yarn, sizing equipment, sizing process, and the operation of the staff.

Many enterprises have expressed their experience in exchanging experience. Only by following the principle that fiber and pulp are compatible with each other and protecting green environment, can we select slurry, be familiar with the properties of slurry, regulate the proportion of immersion and coating, and optimize the matching of slurry according to the quality and quality of yarn, so as to ensure the stability of sizing effect.

Li Xinshun, Shandong's de cotton Limited by Share Ltd, said that how to use or not use PVA without affecting the weaving quality of the yarn does not affect the efficiency and quality of the cloth. This is a systematic problem. It is not enough to start from the pulp enterprise research instead of PVA's environmental slurry. It should also start with raw materials, yarn quality, production equipment, production process and so on.

With the improvement of yarn and fabric grades, the sizing technology becomes more difficult.

For example, in recent years, the variety of yarns has been changing widely, promoting the spread of many kinds of fibers, the development of pure cotton yarn to high branching, the emergence of extra conventional twist yarn, and the high proportion of polyester and cotton blended with cotton. All these have increased the difficulty of sizing technology. In addition, weaving has been developing to no shuttle, high speed and big tension, weaving varieties have high tightness, large width and difficult weaving, and new requirements for sizing and sizing technology have been put forward.